I can share with you what happened after a few big Asian (including Japanese and Korean) supermarkets opened in the Greater Vancouver area in the early 1990s - the smaller shops all either folded or switched their target clientele to SE Asians (Filipinos, Vietnamese) and believe it or not, local Caucasians. Many local Caucasians like the "ambience" of the "Old Chinatown", which fits into the Asia in their imagery - exotic, secretive and a bit dirty.
The cleanest store in the Chinatown area is 168, but it is still far from being acceptable. Kowloon market has a strong stench that makes me nauseated whenever I enter the store; and as a result I stopped going there long time ago.
All the other smaller Vietnamese/Cambodian-owned stores in the Chinatown area are all very cramped and dirty, especially those two at the southeastern corner of Somerset and Booth Sts (one of them has been closed recently). I was told that one of them had regular warning from the City of Ottawa regarding their fish tank. I am actually surprised that some of those stores on Somerset St were not closed down by the city long time ago. The hygiene conditions in those stores are all deplorable.
T&T is not the cleanest either - if you have the chance to visit some of the supermarkets run by the Japanese and Koreans in Vancouver or the US West Coast, you will find them they are even cleaner and tidier than western supermarkets.